The present invention relates to novel fungicidal compositions for the treatment of phytopathogenic diseases of crop plants, especially phytopathogenic fungi, and to a method of combating phytopathogenic diseases on crop plants.
It is known that (E,E)-xcex1-(methoxyimino)-2-[[[[1-(phenyl) ethylidene]amino]oxy]methyl]-benzeneacetic acid methyl ester derivatives have biological activity against phytopathogenic fungi, e.g. known from EP-A-460575 where their properties and methods of preparation are described. On the other hand certain substituted benzophenone compounds with high systemicity are known from EP-A-899255 as plant fungicides for application in various crops of cultivated plants. However, crop tolerance and activity against phytopathogenic plant fungi of the known compounds do not always satisfy the needs of agricultural practice in many incidents and aspects.
It has now been found that the use of
a) (E,E)-xcex1-(methoxyimino)-2-[[[[1-[3(trifluoromethyl) phenyl] ethylidene]amino]oxy]methyl]-benzeneacetic acid methyl ester of formula I 
xe2x80x83in association with
b) a benzophenone of formula II 
xe2x80x83wherein
R1 is hydrogen, halogen, C1-4alkoxy or NO2; and
R2 is C1-6alkyl or optionally substituted benzyl;
is particularly effective in combating or preventing fungal diseases of crop plants. These combinations exhibit synergistic fungicidal activity.
In the above definitions C1-4alkoxy denotes preferably methoxy, ethoxy, n-propoxy or i-propoxy, with methoxy being preferred. C1-6alkyl designates straight chain or branched alkyl, e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec.-butyl, tert.-butyl, or the possible pentyl or hexyl isomers. Preferred are methyl, ethyl, n-propyl, isopropyl, n-butyl and isobutyl. Halogen stands for fluorine, chlorine, bromine and iodine with chlorine and bromine being preferred.
Substitutents of the optionally substituted benzyl group are placed on the phenyl ring with one or two substituents being present and being preferably independently selected from the group comprising halogen or C1-5alkyl. More preferred substitution patterns are 2-methylbenzyl and 2-halobenzyl, e.g. 2-chlorobenzyl and 2-fluorobenzyl.
Throughout this document the expression combination stands for the various combinations of components a) and b) , e.g. in a single xe2x80x9cready-mixxe2x80x9d form, in a combined spray mixture composed from separate formulations of the single active ingredient components, e.g. a xe2x80x9ctank-mixxe2x80x9d, and in a combined use of the single active ingredients when applied in a sequential manner, i.e. one after the other with a reasonably short period, e.g. a few hours or days. The order of applying the components a) and b) is not essential for working the present invention.
The combinations according to the invention may also comprise more than one of the active components b) , if broadening of the spectrum of disease control is desired. For instance, it may be advantageous in the agricultural practice to combine two or three components b) with the any of the compounds of formula I, or with any preferred member of the group of compounds of formula I.
From EP-A-899255 the following specific species of formula II are known:
A preferred embodiment of the present invention is represented by those combinations which comprise as component b) the following subgroups are preferred synergistic partners to the compound of formula I:
compounds of formula II wherein R1 is hydrogen, halogen, methoxy or NO2 and R2 is C1-6alkyl or optionally substituted benzyl; or
compounds of formula II wherein R1 is bromine, chlorine, methoxy or NO2 and R2 is C1-6alkyl or optionally substituted benzyl; or
compounds of formula II wherein R1 is bromine or chlorine, methoxy or NO2 and R2 is methyl, n-butyl or 2-F-benzyl; or
compounds of formula II wherein R1 is bromine and R2 is methyl, n-butyl or 2-F-benzyl.
Preferred individual compounds of formula II are
3-bromo-2xe2x80x2-butoxy-3xe2x80x2,4xe2x80x2-dimethoxy-2,6,6xe2x80x2-trimethyl-benzophenone, and
3-chloro-2xe2x80x2-butoxy-3xe2x80x2,4xe2x80x2-dimethoxy-2,6,6xe2x80x2-trimethyl-benzophenone.
The active ingredient combinations are effective against phytopathogenic fungi belonging to the following classes: Ascomycetes (e.g. Venturia, Podosphaera, Erysiphe, Monilinia, Mycosphaerella, Uncinula); Basidiomycetes (e.g. the genus Hemileia, Rhizoctonia, Pucinia); Fungi imperfecti (e.g. Botrytis, Helminthosporium, Rhynchosporium, Fusarium,
Septoria, Cercospora, Alternaria, Pyricularia and Pseudocercosporella herpotrichoides); Oomycetes (e.g. Phytophthora, Peronospora, Bremia, Pythium, Plasmopara).
Target crops for the areas of indication disclosed herein comprise within the scope of this invention e.g. the following species of plants: cereals (wheat, barley, rye, oats, rice, sorghum and related crops); beet (sugar beet and fodder beet); pomes, stone fruit and soft fruit (apples, pears, plums, peaches, almonds, cherries, strawberries, raspberries and black-berries); leguminous plants (beans, lentils, peas, soybeans); oil plants (rape, mustard, poppy, olives, sunflowers, coconut, castor oil plants, cocoa beans, groundnuts); cucumber plants (marrows, cucumbers, melons); fibre plants (cotton, flax, hemp, jute); citrus fruit (oranges, lemons, grapefruit, mandarins); vegetables (spinach, lettuce, asparagus, cabbages, carrots, onions, tomatoes, potatoes, paprika); lauraceae (avocados, cinnamon, camphor); or plants such as maize, tobacco, nuts, coffee, sugar cane, tea, vines, hops, turf, bananas and natural rubber plants, as well as ornamentals (flowers, shrubs, broad-leaved trees and evergreens, such as conifers). This list does not represent any limitation.
The combinations of the present invention may also be used in the area of protecting technical material against attack of fungi. Technical areas include wood, paper, leather, constructions, cooling and heating systems, ventilation and air conditioning systems, and the like. The combinations according the present invention can prevent the disadvantageous effects such as decay, discoloration or mold.
The combinations according to the present invention are particularly effective against powdery mildews and rusts, pyrenophora, rhynchosporium, tapesia, fusarium and leptosphaeria fungi, in particular against pathogens of monocotyledonous plants such as cereals, including wheat and barley. They are furthermore particularly effective against downy mildew species, powdery mildews, leaf spot diseases and rusts in dicotyledonous plants.
The amount of combination of the invention to be applied, will depend on various factors such as the compound employed, the subject of the treatment (plant, soil, seed), the type of treatment (e.g. spraying, dusting, seed dressing), the purpose of the treatment (prophylactic or therapeutic), the type of fungi to be treated and the application time.
It has been found that the use of compounds of formula II in combination with the compound of formula I surprisingly and substantially enhance the effectiveness of the latter against fungi, and vice versa. Additionally, the method of the invention is effective against a wider spectrum of such fungi that can be combated with the active ingredients of this method, when used solely.
The weight ratio of a):b) is so selected as to give a synergistic fungicidal action. In general the weight ratio of a):b) is between 15:1 and 1:80. The synergistic action of the composition is apparent from the fact that the fungicidal action of the composition of a)+b) is greater than the sum of the fungicidal actions of a) and b).
The method of the invention comprises applying to the treated plants or the locus thereof in admixture or separately, a fungicidally effective aggregate amount of a compound of formula I and a compound of component b).
The term locus as used herein is intended to embrace the fields on which the treated crop plants are growing, or where the seeds of cultivated plants are sown, or the place where the seed will be placed into the soil. The term seed is intended to embrace plant propagating material such as cuttings, seedlings, seeds, germinated or soaked seeds.
The novel combinations are extremely effective on a broad spectrum of phytopathogenic fungi. Some of them have a systemic action and can be used as foliar and soil fungicides and for seed dressing.
The fungicidal combinations are of particular interest for controlling a large number of fungi in various crops or their seeds, especially wheat, rye, barley, oats, rice, maize, lawns, cotton, soybeans, coffee, sugarcane, fruit and ornamentals in horticulture and viticulture, in vegetables such as cucumbers, beans and cucurbits, and in field crops such as potatoes, peanuts, tobacco and sugarbeets.
The combinations are applied by treating the fungi or the seeds, plants or materials threatened by fungus attack, or the soil with a fungicidally effective amount of the active ingredients.
The agents may be applied before or after infection of the materials, plants or seeds by the fungi.
The novel combinations are particularly useful for controlling the following plant diseases:
Erysiphe graminis in cereals,
Erysiphe cichoracearum and Sphaerotheca fuliginea in cucurbits,
Podosphaera leucotricha in apples,
Uncinula necator in vines,
Puccinia species in cereals,
Rhizoctonia species in cotton, potatoe, rice and lawns,
Ustilago species in cereals and sugarcane,
Venturia inaequalis (scab) in apples,
Helminthosporium species in cereals,
Septoria nodorum in wheat,
Septoria tritici in wheat wheat,
Rhynchosporium secalis on barley,
Botrytis cinerea (gray mold) in strawberries, tomatoes and grapes,
Cercospora arachidicola in groundnuts,
Peronospora tabacina in tobacco, or other Peronospora in various crops,
Pseudocercosporella herpotrichoides in wheat and barley,
Pyrenophera teres in barley,
Pyricularia oryzae in rice,
Phytophthora infestans in potatoes and tomatoes,
Fusarium and Verticillium species in various plants,
Plasmopara viticola in grapes,
Alternaria species in fruit and vegetables,
Pseudoperonospora cubensis in cucumbers,
Mycosphaerella fijiensis in banana,
Colleotrichum species in various crops.
When applied to the plants the compound of formula I is applied at a rate of 25 to 250 g/ha, particularly 50 to 150 g/ha, e.g. 75, 100, 125 or 150g/ha, in association with 20 to 2000 g/ha, particularly 20 to 1000 g/ha, e.g. 20.g/ha, 30 g/ha, 40 g/ha, 75 g/lha, 80 g/ha, 100 g/ha, 125 g/ha, 150 g/ha, 175 g/ha, 200 g/ha, 300 g/ha, 500 g/ha, 1000 g/ha, 1200 g/ha, 1500 g/ha, 2000 g/ha of a compound of component b).
In agricultural practice the application rates of the combination depend on the type of effect desired, and range from 0.02 to 3 kg of active ingredient per hectare.
When the active ingredients are used for treating seed, rates of 0.001 to 50 g a.i. per kg, and preferably from 0.01 to 10 g per kg of seed are generally sufficient.
The invention also provides fungicidal compositions comprising a compound of formula I and a compound of component b).
The composition of the invention may be employed in any conventional form, for example in the form of a twin pack, an instant granulate, a flowable formulation, an emulsion concentrate or a wettable powder in combination with agriculturally acceptable adjuvants. Such compositions may be produced in conventional manner, e.g. by mixing the active ingredients with appropriate adjuvants (diluents or solvents and optionally other formulating ingredients such as surfactants). Also conventional slow release formulations may be employed where long lasting efficacy is intended.
Particularly formulations to be applied in spraying forms such as water dispersible concentrates or wettable powders may contain surfactants such as wetting and dispersing agents, e.g. the condensation product of formaldehyde with naphthalene sulphonate, an alkylarylsulphonate, a lignin sulphonate, a fatty alkyl sulphate, and ethoxylated alkylphenol and an ethoxylated fatty alcohol.
A seed dressing formulation is applied in a manner known per se to the seeds employing the combination of the invention and a diluent in suitable seed dressing formulation form, e.g. as an aqueous suspension or in a dry powder form having good adherence to the seeds. Such seed dressing formulations are known in the art. Seed dressing formulations may contain the single active ingredients or the combination of active ingredients in encapsulated form, e.g. as slow release capsules or microcapsules.
In general, the formulations include from 0.01 to 90% by weight of active agent, from 0 to 20% agriculturally acceptable surfactant and 10 to 99.99% solid or liquid adjuvant(s), the active agent consisting of at least the compound of formula I together with a compound of component b), and optionally other active agents, particularly microbides or conservatives or the like. Concentrated forms of compositions generally contain in between about 2 and 80%, preferably between about 5 and 70% by weight of active agent. Application forms of formulation may for example contain from 0.01 to 20% by weight, preferably from 0.01 to 5% by weight of active agent. Whereas commercial products will preferably be formulated as concentrates, the end user will normally employ dilute formulations.